The present invention relates to a method for the preparation of excellent organic compost by achieving an aerobic fermentation of excretions from domestic animals.
A variety of methods have been proposed to compost feces of fowls or pigs or other excretions from domestic animals. For example, it is generally known to achieve an aerobic fermentation of excretions from domestic animals, in which sawdust, rice hulls, or wood chips have been incorporated as an agent for adjusting the water content of the mixture to be suitable for aerobic fermentation (65% by weight or less). However, as these water content-adjusting agents are organic materials which have difficulty in decomposition, it takes a long time to achieve the complete fermentation, and hence a large fermentation vessel is necessary. Moreover, the resultant compost product has a small bulk specific gravity, which leads to a disadvantage that the product when applied on the field is likely to be driven away by wind or rain.
Another method of achieving an aerobic fermentation of excretions from domestic animals has been proposed, in which zeolite is incorporated to control the water content. The incorporation of zeolite increases fertilizing and soil-conditioning effects of the product because of the water-retentive and base-exchanging actions of zeolite. It is also expected that offensive odors are prevented by the deodorizing action of zeolite. Moreover, a compost product in which zeolite is incorporated has a large bulk specific gravity, which prevents flowing of the product by wind or rain when applied on the field. However, a considerably large amount of zeolite must be incorporated in excretions from domestic animals for these purposes because the water content suitable for aerobic fermentation of the excretion/zeolite mixture is as low as 50% by weight or less, preferably 40% by weight or less. For example, in order to adjust the water content of fowl feces containing 72% by weight water to 50% by weight, zeolite must be incroporated in an amount of about 55% by weight of the fowl feces. The incorporation of such a large amount of zeolite relatively decreases the content of organic materials in the mixture, which inhibits desirable aerobic fermentation.